Picture quality adjustment method and picture quality adjustment apparatus

ABSTRACT

A picture quality adjustment method is disclosed wherein, if a user performs a picture quality adjustment operation once, even if a picture quality adjustment operation is not performed any more for video software of the same authoring, genre or image characteristic, an image of an optimum picture quality can be obtained. When a disk ID of a disk to be played back is not stored in a first memory, it is discriminated whether or not characteristic describing information then and corresponding picture quality adjustment data are stored in a second memory. If such data are not stored, then the picture quality is set to a preset condition, but if such data are stored, then the picture quality adjustment data are read out and picture quality adjustment is executed. If the user instructs to store the picture quality adjustment data then after picture quality adjustment is performed or without performing picture quality adjustment, then the picture quality adjustment data then are written in a corresponding relationship to the disk ID and the characteristic describing information into the first memory and in a corresponding relationship to the characteristic describing information into the second memory. When the same disk is played back layer, the picture quality adjustment data corresponding to the disk are read out from the first memory to execute picture quality adjustment.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a picture quality adjustment method anda picture quality adjustment apparatus for a video outputting apparatussuch as a DVD (Digital Versatile Disc) player or a set top box.

[0002] Where a video signal outputted from a video outputting apparatussuch as a DVD player or a set top box is signaled to and displayed on avideo display apparatus, in order to adjust the picture quality of animage to be displayed such as an average brightness or a brightnesscontrast, a method is conventionally employed wherein an adjustmentoperation is performed on the video display apparatus side to adjust thepicture quality.

[0003] However, video software (contents) which is authored in variousmanners, belongs to various genres (categories) or has various imagecharacteristics may be outputted from a video outputting apparatus suchas a DVD player or a set top box.

[0004] Therefore, it is difficult to always obtain an image of anoptimum picture quality by a single operation for adjustment of thepicture quality on the video display apparatus side. Thus, the user mustperform a picture quality adjustment operation every time the authoring,genre or image characteristic of video software to be outputted from thevideo outputting apparatus changes. Therefore, a heavy burden is imposedon the user in terms of the picture quality adjustment operation.

SUMMARY OF THE INVENTION

[0005] It is an object of the present invention to provide a picturequality adjustment method and a picture quality adjustment apparatuswherein, if a user performs a picture quality adjustment operation once,even if a picture quality adjustment operation is not performed any morefor video software of the same authoring, genre or image characteristic,an image of an optimum picture quality can be obtained whilesignificantly decreasing the burden to the user in picture qualityadjustment operation.

[0006] In order to attain the object described above, according to anaspect of the present invention, there is provided a picture qualityadjustment method, comprising the steps of writing a picture qualityadjustment condition for a video signal as picture quality adjustmentdata in a corresponding relationship to video identification informationfor specifying a video or characteristic describing information whichdescribes an image characteristic into a memory which is capable ofkeeping storage contents thereof without a power supply or with a backuppower supply, and reading out, upon outputting of a video, if the videoidentification information or the characteristic describing informationof a video signal to be outputted and the corresponding picture qualityadjustment data are stored in the memory, the picture quality adjustmentdata from the memory and setting a picture quality adjustment conditionfor the video signal to be outputted in accordance with the read outpicture quality adjustment data.

[0007] According to another aspect of the present invention, there isprovided a picture quality adjustment apparatus, comprising a memorycapable of keeping storage contents thereof without a power supply orwith a backup power supply, and a control section for writing a picturequality adjustment condition for a video signal as picture qualityadjustment data in a corresponding relationship to video identificationinformation for specifying a video or characteristic describinginformation which describes an image characteristic into the memory andreading out, upon outputting of a video, if the video identificationinformation or the characteristic describing information of a videosignal to be outputted and the corresponding picture quality adjustmentdata are stored in the memory, the picture quality adjustment data fromthe memory and setting a picture quality adjustment condition for thevideo signal to be outputted in accordance with the read out picturequality adjustment data.

[0008] With the picture quality adjustment method and the picturequality adjustment apparatus, if a user performs a picture qualityadjustment operation once, then even if a picture quality adjustmentoperation is not performed any more for video software of the sameauthoring, genre or image characteristic, an image of an optimum picturequality can be obtained while significantly decreasing the burden to theuser in picture quality adjustment operation.

[0009] It is to be noted that, where a video outputting apparatus is avideo playback apparatus such as a DVD player which plays back, from arecording medium such as a disk, videos recorded on the recordingmedium, the video identification information above includes informationfor specifying the recording medium such as a disk ID (identificationinformation), and generally is information which specifies a program, agenre or a scene.

[0010] If a disk has no disk ID recorded thereon, then headerinformation of the disk is combined suitably in accordance with apredetermined rule such as a combination of the number of chaptersincluded in the disk and a play time, and the combination is used as adisk ID of the disk.

[0011] Further, the characteristic describing information above is adescription of image characteristic for each unit of images developed ina time series such as programs or scenes, and is hereinafter referred toas “metadata”.

[0012] The above and other objects, features and advantages of thepresent invention will become apparent from the following descriptionand the appended claims, taken in conjunction with the accompanyingdrawings in which like parts or elements denoted by like referencesymbols.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a block diagram showing a DVD player to which thepresent invention is applied;

[0014]FIG. 2 is a similar view but showing another DVD player to whichthe present invention is applied;

[0015]FIGS. 3 and 4 are flow charts illustrating an example of anadjustment processing routine performed by a system controller of theDVD player of FIG. 1 or 2;

[0016]FIGS. 5A and 5B are views illustrating an example of a storagecondition of memories of the DVD player of FIG. 1 or 2;

[0017]FIG. 6 is a block diagram showing a digital TV receiver to whichthe present invention is applied; and

[0018]FIG. 7 is a similar view but showing another digital TV receiverto which the present invention is applied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1. Embodiments wherein the invention is applied to a DVD player .. . FIGS. 1 to 5B

[0020] 1-1. Outline of the player system . . . FIGS. 1 and 2

[0021]FIGS. 1 and 2 show different embodiments wherein the presentinvention is applied to a DVD player.

[0022] Referring to FIGS. 1 and 2, a video signal and an audio signal ina form compressed, coded and multiplexed in conformity with, forexample, the MPEG (Moving Picture Experts Group) 2 standards and a diskID are recorded on a disk 11.

[0023] It is to be noted that a plurality of pieces of video software(contents) may be recorded on the same disk. In this instance, videoidentification information (information for specifying videos) isdifferent from the disk ID. However, the following description is givenparticularly of a case wherein such video identification information isa disk ID.

[0024] Such metadata as described hereinabove can be recorded on thedisk 11, and in the present embodiments, it is assumed that metadata arerecorded on some disks. FIG. 1 shows a DVD player for a disk on whichmetadata are recorded in a multiplexed condition separately from a videoand audio data stream while FIG. 2 shows another DVD player for anotherdisk on which metadata are recorded in a multiplexed form in andtogether with a video and audio data stream.

[0025] The metadata include data of an average brightness, a brightnesscontrast, a ratio between bright and dark regions, a brightnesstransition coefficient on a time series, a color balance, presence orabsence of application of a visual effect and so forth as imagecharacteristics. Where the metadata are recorded in a multiplexed formseparately from a video and audio data stream, it describes imagecharacteristics such as information representative of a section of videoinformation, the lowest brightness in the section, the highestbrightness, an average brightness and so forth. The informationrepresentative of a section is described with a presentation timestampor the like.

[0026] The disk 11 is driven to rotate by a drive mechanism 21 whichincludes a disk motor and a driving circuit for the disk motor notshown. An optical head 12 is driven by a drive mechanism 22 whichincludes a feed motor and tracking and focusing actuators not shown. Thedrive mechanism 21 and 22 are controlled by a servo controller 23, whichin turn is controlled by a system controller 24 which controls theentire player system.

[0027] An operation section 25 such as a remote controller is providedfor the system controller 24 such that the user can perform adjustmentof the picture quality of a playback image through the operation section25. Also a display section 26 including a display unit such as a liquidcrystal display device not shown is provided for the system controller24.

[0028] A first memory 27 and a second memory 28 are connected to thesystem controller 24. Each of the first memory 27 and the second memory28 is formed from an EAROM (Electrically Alterable Read Only Memory) ora flash memory and can keep stored contents thereof without using apower supply or through the use of a backup power supply. Picturequality adjustment data can be written in a corresponding relationshipto a disk ID in the first memory 27 while the picture quality adjustmentdata can be written in a corresponding relationship to metadata in thesecond memory 28. The first memory 27 and the second memory 28 may betwo memories physically separate from each other or two different areasof one memory.

[0029] Alternatively, each or both of the first memory 27 and the secondmemory 28 may be an external storage medium such as a memory card. Wherean external storage medium is used, by using different external storagemedia depending upon whether a CRT display unit or a liquid crystalprojector display unit is used as a video display apparatus, the videodisplay apparatus having different display characteristics can beselectively used appropriately. Also it is possible to prepare inadvance an external storage medium in which picture quality adjustmentdata and metadata produced with a displaying performance of a videodisplay apparatus taken into consideration are written.

[0030] Information read from the disk 11 and outputted from the opticalhead 12 is supplied to a radio frequency (RF) processor 13. The RFprocessor 13 includes a generation section for generating a trackingerror signal and a focusing error signal, an error correction section, abuffer section, a data stream detection and separation section, and ametadata detection and separation section not shown. Thus, a disk ID, atracking error signal and a focusing error signal, and a video and audiodata stream of the MPEG 2 standards are obtained from the RF processor13.

[0031] Where the metadata are in the multiplexed form separately from avideo and audio data stream, the metadata are detected and separated bythe RF processor 13 and fetched by the system controller 24 as seen fromFIG. 1.

[0032] It is to be noted that, where caption data are multiplexed, theyare detected and separated by the RF processor 13 and are played back bya caption playback section not shown and then superimposed with thevideo signal by a video playback processing section 15 which ishereinafter described.

[0033] The disk ID is fetched by the system controller 24. The trackingerror signal and the focusing error signal are supplied to the servocontroller 23, by which they are used for tracking servo control andfocusing servo control of the optical head 12.

[0034] The video and audio data stream from the RF processor 13 isseparated into a video data stream and an audio data stream and thendecompressed and decoded into video data and audio data by an MPEGdecoder 14.

[0035] Where the video and audio data stream has metadata multiplexedtherein, the metadata are demultiplexed from the video and audio datastream by the MPEG decoder 14 and fetched by the system controller 24 asseen in FIG. 2.

[0036] The video data are outputted from the MPEG decoder 14 andseparated into brightness data and color difference data by the videoplayback processing section 15. The video playback processing section 15further performs picture quality adjustment processing for the thusseparated brightness data or color difference data and then synthesizesthe brightness data and the color difference data to obtain video dataof the same format as that of the video data inputted to the videoplayback processing section 15.

[0037] The picture quality in this instance includes, for thebrightness, the lowest brightness, the highest brightness, an averagebrightness, a brightness contrast, and a contour emphasis (contourcompensation) characteristic and, for the color, a color gain (colorconcentration), a hue and so forth.

[0038] The video data outputted from the video playback processingsection 15 are converted on one hand into an analog video signal of theNTSC system, the PAL system or the progressive system by an analogoutput encoder 16. The analog video signal obtained is outputted to avideo display apparatus such as a CRT display apparatus or a liquidcrystal projector display apparatus not shown, an analog video and audioapparatus such as an analog TV (Television) receiver or some otheranalog video apparatus not shown.

[0039] The video data outputted from the video playback processingsection 15 are on the other hand outputted, after they are convertedinto video data of some other format by a digital output encoder 17 orwithout undergoing such conversion, to a digital video and audioapparatus such as a digital TV receiver or some other digital videoapparatus not shown through a digital interface 18 such as an interfacecomplying with the IEEE (Institute of Electrical and ElectronicsEngineers) 1394 standards.

[0040] The audio data outputted from the MPEG decoder 14 are subject toaudio playback processing by an audio playback processing section 19.Though not shown, in conformity with the video data outputted from thevideo playback processing section 15, the audio data outputted from theaudio playback processing section 19 are on one hand converted into ananalog audio signal and outputted to an audio outputting apparatus suchas a speaker apparatus or a headphone apparatus, an analog video andaudio apparatus such as an analog TV receiver or some other analog audioapparatus not shown, and on the other hand outputted through the digitalinterface 18 after multiplexed with the video data after converted intoaudio data of some other format or without undergoing such conversion orthrough another digital interface not shown without being multiplexedwith the video data to a digital video and audio apparatus such as adigital TV receiver or some other digital audio apparatus not shown.

[0041] 1-2. Picture quality adjustment . . . FIGS. 3 to 5B

[0042] The player system of FIG. 1 or 2 having such a construction asdescribed above performs picture quality adjustment, for example, inaccordance with an adjustment process routine illustrated in FIGS. 3 and4 while a playback image is displayed on an image display apparatus notshown connected to the player system.

[0043] In particular, in the adjustment process routine illustrated inFIGS. 3 and 4, after playback of a certain disk is started, the systemcontroller 24 first fetches the disk ID of the disk in step 31illustrated in FIG. 3. If the disk does not have a disk ID recordedthereon, then header information of the disk is combined in accordancewith a predetermined rule to produce a disk ID for the disk as describedhereinabove.

[0044] Then in step 32, the system controller 24 discriminates whetheror not the disk ID is stored in the first memory 27. When the disk ofthe disk ID is played back for the first time, the first memory 27 doesnot have the disk ID stored therein.

[0045] If the disk ID is not stored in the first memory 27, then theprocessing advances from step 32 to step 33, in which the systemcontroller 24 discriminates whether or not metadata are detected. Ifmetadata are not detected, then the processing advances from step 33 tostep 51 directly without performing adjustment of the picture quality ofthe playback image.

[0046] However, if metadata are detected in step 33, then the processingadvances from step 33 to step 34, in which the system controller 24controls the display section 26 to display to inform the user thatmetadata are detected. Then, the processing advances to step 35, inwhich the system controller 24 discriminates whether or not the metadatathen and picture quality adjustment data corresponding to the metadataare stored in the second memory 28.

[0047] If the metadata then and the corresponding picture qualityadjustment data are not stored in the second memory 28, then theprocessing advances from step 35 to step 41, in which the systemcontroller 24 sets the picture quality of the playback image to apicture quality set in advance, for example, to a picture quality in astate wherein no picture quality adjustment is performed for brightnessdata and color difference data by the video playback processing section15. Thereafter, the processing advances to step 51.

[0048] On the contrary if the metadata then and the correspondingpicture quality adjustment data are stored in the second memory 28 instep 35, then the processing advances from step 35 to step 43, in whichthe system controller 24 reads out the picture quality adjustment datacorresponding to the metadata then from the second memory 28. Then, theprocessing advances to step 44, in which the system controller 24executes picture quality adjustment in accordance with the thus read outpicture quality adjustment data. Thereafter, the processing advances tostep 51.

[0049] If the disk ID fetched or produced in step 31 is stored in thefirst memory 27 in step 32, then the processing advances from step 32 tostep 45, in which the system controller 24 reads out the picture qualityadjustment data corresponding to the disk ID from the first memory 27.Thereafter, the processing advances to step 46, in which the systemcontroller 24 executes picture quality adjustment in accordance with thethus read out picture quality adjustment data. Then, the processingadvances to step 51.

[0050] Referring now to FIG. 4, in step 51, the system controller 24discriminates whether or not a picture quality adjustment operation isperformed by the user.

[0051] The user can perform adjustment or alteration of the picturequality through a picture quality adjustment operation of the operationsection 25 not only when the picture quality of the playback image isnot adjusted because no metadata are detected but also when the picturequality of the playback image is not set to the picture qualitycondition set in advance in step 41, when picture quality adjustment isperformed in accordance with the picture quality adjustment datacorresponding to the metadata stored in the second memory 28 in step 44or when picture quality adjustment is performed in accordance with thepicture quality adjustment data corresponding to the disk ID stored inthe first memory 27 in step 46.

[0052] Then, when the user performs a picture quality adjustmentoperation, the system controller 24 advances the processing from step 51to step 52, in which it alters the picture quality adjustment data inresponse to the adjustment operation of the user and executes picturequality adjustment in accordance with the adjustment operation of theuser. Thereafter, the processing advances to step 53. On the other hand,if the user does not perform a picture quality adjustment operation instep 51, then the processing advances from step 51 to step 53 directly.

[0053] In step 53, the system controller 24 controls the display section26 to display for inquiry to the user of whether or not the picturequality adjustment condition then should be stored as a picture qualityadjustment condition corresponding to the disk or a picture qualityadjustment condition corresponding to the metadata then.

[0054] Not only when a picture quality adjustment operation is performedbut also when a picture quality adjustment operation is not performed,the user can store the picture quality adjustment condition then aspicture quality adjustment condition corresponding to the disk or apicture quality adjustment condition corresponding to the metadata then.If the user wants to store the picture quality adjustment conditionthen, it will perform an operation therefor, but otherwise, it willperform an operation therefor.

[0055] Then, the processing advances from step 53 to step 54, in whichthe system controller 24 discriminates whether or not the response ofthe user represents the storage. If the response represents the storage,then the processing advances from step 54 to step 55, in which thesystem controller 24 discriminates whether or not the first memory 27has some free or unoccupied area. If the first memory 27 has some freearea, then the processing advances from step 55 to step 56, in which thesystem controller 24 writes the picture quality adjustment data then ina corresponding relationship to the disk ID of the disk into the firstmemory 27. Thereafter, the processing advances to step 58.

[0056] In this instance, if metadata are detected, then the systemcontroller 24 writes the picture quality adjustment data then in acorresponding relationship not only to the disk ID but also to themetadata into the first memory 27 and further writes the picture qualityadjustment data then in a corresponding relationship to the metadatainto the second memory 28.

[0057] On the other hand, if the picture quality adjustment data arealready stored in a corresponding relationship to the disk ID in thefirst memory 27, then the system controller 24 rewrites the picturequality adjustment data. Further, if the picture quality adjustment dataare stored in a corresponding relationship to the metadata in the secondmemory 28, then the system controller 24 rewrites the picture qualityadjustment data.

[0058] If the first memory 27 does not have a free area in step 55, thenthe processing advances from step 55 to step 57, in which an editingprocess is executed, whereafter the processing advances to step 58.

[0059] The editing process in step 57 may be to erase those ones of diskIDs and corresponding picture quality adjustment data stored in thefirst memory 27 which were registered oldest and store the disk ID thenand the corresponding picture quality adjustment data or to erase theoldest disk ID and corresponding picture quality adjustment data anddetermine whether or not the disk ID then and the corresponding picturequality adjustment data should be stored in accordance with selection ofthe user.

[0060] On the other hand, if it is discriminated in step 54 that theresponse of the user does not represent an intention of the storage,then the processing advances from step 54 to step 58 directly.

[0061] The user may not intend storage of the picture quality adjustmentcondition, for example, when the disk 11 is played back temporarilyusing a liquid crystal projector display apparatus as the video displayapparatus in place of a CRT display apparatus and the user does not wantthat the picture quality adjustment state set and stored for thenormally used CRT display apparatus is altered.

[0062] In step 58, it is discriminated whether or not the disk is beingplayed back. If the disk is being played back, then the processingreturns from step 58 to step 33 so that the processing beginning withstep 33 is repeated. If the playback of the disk comes to an end, thenthe adjustment process is ended as well.

[0063] It is to be noted that, for a user who considers that it iscumbersome to respond to the display (inquiry) in step 53 whether or notthe picture quality adjustment condition then should be stored everytime, the adjustment process routine to be executed by the systemcontroller 24 may be set otherwise such that the discrimination in step54 normally is to store the picture quality adjustment condition then.

[0064] As an example, it is assumed that, when the first memory 27 andthe second memory 28 have no picture quality adjustment data storedtherein, a disk of the disk ID of “D1” on which metadata M1 and M2representative of image characteristics for two video scenes arerecorded is played back first.

[0065] At this instance, for example, if the image characteristic of thevideo scene whose image characteristic is indicated by the metadata M1is that “the average brightness is high” and the user adjusts thepicture quality so as to lower the average brightness whereas the imagecharacteristic of the video scene whose image characteristic isindicated by the metadata M2 is that “the brightness contrast is low”and the user adjusts the picture quality so as to raise the brightnesscontrast and then the user issues an instruction to store the individualpicture quality adjustment data then, then the individual picturequality adjustment data are written in a corresponding relationship tothe disk ID “D1” and in a corresponding relationship to the metadata M1and M2 into the first memory 27 as seen in FIG. 5A and further theindividual picture quality adjustment data are written in acorresponding relationship to the metadata M1 and M2 into the secondmemory 28 as seen in FIG. 5B.

[0066] It is assumed that, in this state, another disk of the disk ID of“D2” on which no metadata is recorded is played back subsequently. Atthis time, if the user adjusts the picture quality and issues aninstruction to store the adjustment data then, then the picture qualityadjustment data then are written in a corresponding relationship to thedisk ID “D2” into the first memory 27 as seen in FIG. 5A.

[0067] Then, it is assumed that a further disk of the disk ID of “D3” onwhich metadata M1 indicative of an image characteristic for a certainvideo scene is played back subsequently. The metadata M1 and thecorresponding picture quality adjustment data are already stored in thesecond memory 28. Accordingly, at this time, picture quality adjustmentof the video scene whose image characteristic is indicated by themetadata M1 is executed in step 44 in accordance with the picturequality adjustment data corresponding to the metadata M1 read out fromthe second memory 28.

[0068] On the other hand, if the user issues an instruction to store thepicture quality adjustment data then without performing picture qualityadjustment or after it performs picture quality adjustment, then thepicture quality adjustment data are written in a correspondingrelationship to the disk ID “D3” and also in a correspondingrelationship to the metadata M1 into the first memory 27 as seen in FIG.5A, and the picture quality adjustment data corresponding to themetadata M1 stored in the second memory 28 are rewritten with thepicture quality adjustment data then as seen in FIG. 5B.

[0069] Thereafter, if the disk of the disk ID of “D1” on which themetadata M1 and M2 are recorded is played back, then picture qualityadjustment of the video scene whose image characteristic is indicated bythe metadata M1 is executed in step 46 in accordance with the picturequality adjustment data read out from the first memory 27 andcorresponding to the disk ID “D1” and the metadata M1. Meanwhile,picture quality adjustment of the video scene whose image characteristicis indicated by the metadata M2 is executed in step 46 in accordancewith the picture quality adjustment data read out from the first memory27 and corresponding to the disk ID “D1” and the metadata M2.

[0070] In the player system of FIG. 1 or 2 described above, when a userperforms an operation to store picture quality adjustment data, picturequality adjustment data then are written into the first memory 27 in acorresponding relationship to the disk ID and further in a correspondingrelationship to metadata then. Then, when the disk is to be played backthereafter, the picture quality adjustment data corresponding to thedisk and corresponding to metadata then are read out from the firstmemory 27 and a picture quality adjustment condition is set inaccordance with the picture quality adjustment data. Consequently, theuser can obtain a playback image of an optimum picture quality from thesame disk without performing a picture quality adjustment operation in aunit of a video every time playback is to be performed.

[0071] Further, the picture quality adjustment data are written in acorresponding relationship to the metadata into the second memory 28 inaccordance with an operation history of the user. Then, when the disk onwhich the same metadata are recorded is to be played back later, picturequality adjustment data corresponding to the metadata are read out toset a picture quality adjustment condition. Consequently, the user canobtain a playback image of an optimum picture quality from the disk onwhich the same metadata are recorded without performing a picturequality adjustment operation every time playback is to be performed.

[0072] 1-3. Another example of the first memory

[0073] In the player system of FIG. 1 or 2, if it is intended to store adisk ID and corresponding picture quality adjustment data of a largenumber of disks into the first memory 27, then a memory having a largecapacity is required for the first memory 27 or such an editing processas described hereinabove is required.

[0074] Thus, if the disk 11 is of the recordable type or the rewritabletype, then part of the area of the disk 11 may be utilized as the firstmemory. In this instance, although a circuit for writing picture qualityadjustment data is required, the system controller 24 may be constructedso as to store picture quality adjustment data for a disk to be playedback into an internal RAM such that, when the user performs an operationto store picture quality adjustment data, picture quality adjustmentdata then are written into the area of the disk 11 which is utilized asthe first memory, and then when the same disk is to be played back, thepicture quality adjustment data are fetched together with the disk IDfrom the disk and stored into the internal RAM.

[0075] 1-4. A further example of the first memory

[0076] According to the first memory 27 shown in FIG. 5A, metadata arenot recorded on the disk whose disk ID is “D2”, and the disk ID “D2” andcorresponding picture quality adjustment data are stored without beingmade correspond to metadata into the first memory 27. For a disk onwhich metadata are not recorded in this manner, the first memory 27 canbe used in the following manner.

[0077] It is presumed that, with the disk whose disk ID is “D2”, it isnecessary to change the picture quality between a plurality of sectionssuch as a front half section and a rear half section. In this instance,the system controller 24 produces information pieces T1, T2 and so onrepresentative of individual sections based on information of apresentation timestamp and so forth and writes picture qualityadjustment data C1, C2 and so on of the individual sections in acorresponding relationship to the information pieces T1, T2 and so on inplace of metadata into the first memory 27.

[0078] Then, when the same disk is to be played back, since theinformation pieces T1, T2 and so on representative of the individualsections are recorded in the metadata describing column for the diskwhose disk ID in the disk ID describing column in the first memory 27 isD2, the system controller 24 detects the individual sections andexecutes picture quality adjustment in the individual sections inaccordance with the corresponding picture quality adjustment data C1, C2and so on.

[0079] Where the first memory of the construction described above isused, even when a disk on which metadata are not recorded is to beplayed back, the picture quality adjustment condition can be changedover automatically in a plurality of sections.

[0080] 2. Other embodiments . . . FIGS. 6 and 7

[0081] A picture quality adjustment method of the present invention canbe applied not only to a video playback apparatus such as a DVD playerbut also to a video outputting apparatus such as a TV receiver.

[0082] Also in TV broadcasting, video software (contents) which isauthored in various manners, belongs to various genres or has variousimage characteristics is broadcast. Particularly in digital TVbroadcasting, a program ID, a genre ID or the like is transmitted, andcharacteristic describing information (metadata) can be inserted intoand transmitted together with a program or a scene.

[0083]FIGS. 6 and 7 show embodiments wherein the present invention isapplied to a digital TV receiver. Particularly, FIG. 6 shows anembodiment wherein metadata are multiplexed and broadcast separatelyfrom a video and audio data stream, and FIG. 7 shows another embodimentwherein metadata are multiplexed into and broadcast together with avideo and audio data stream.

[0084] Referring to FIGS. 6 and 7, a broadcast reception section 62receives and selects a broadcast digital TV signal under the receptioncontrol of a system controller 24 in accordance with an operation by anoperation section 25. The received and selected signal is supplied to aRF processor 63. The RF processor 63 includes a demodulation section, anerror correction section, a data stream detection and separation sectionand a metadata detection and separation section not shown. Thus, aprogram ID (or genre ID) and a video and audio data stream of the MPEGsystem are obtained from the RF processor 63.

[0085] Where metadata are multiplexed separately from a video and audiodata stream, the metadata are detected and separated by the RF processor63 and fetched by the system controller 24 as seen in FIG. 6.

[0086] The program ID (or genre ID) is fetched by the system controller24. The video and audio data stream from the RF processor 63 isseparated into a video data stream and an audio data stream and thendecompressed and decoded into video data and audio data by an MPEGdecoder 64.

[0087] On the other hand, where the metadata are multiplexed in thevideo and audio data stream, the metadata are separated from the videoand audio data stream and fetched by the system controller 24 as seen inFIG. 7.

[0088] The video data outputted from the MPEG decoder 64 are separatedinto brightness data and color difference data by a video playbackprocessing section 65. The video playback processing section 65 furtherperforms a picture quality adjustment process for the thus separatedbrightness data or color difference data and then synthesizes thebrightness data and the color difference data to obtain video data of aformat same as that of the video data inputted to the video playbackprocessing section 65. The video data outputted from the video playbackprocessing section 65 are converted into an analog video signal of theNTSC system or like.

[0089] The audio data outputted from the MPEG decoder 64 undergo anaudio playback process and then are converted into an analog audiosignal by an audio playback processing section 69.

[0090] Also each of the digital TV receivers described above withreference to FIGS. 6 and 7 includes the first memory 27 and the secondmemory 28, and picture quality adjustment data are written in acorresponding relationship to a program ID (or genre ID) into the firstmemory 27. Then, when a program in which the same program ID (or genreID) is inserted is received next, the picture quality adjustment datacorresponding to the program ID (or genre ID) are read out from thefirst memory 27 to set a picture quality adjustment condition. On theother hand, the picture quality adjustment data are written in acorresponding relationship to metadata into the second memory 28, andthen when a program or a scene in which the same metadata are insertedis received next, the picture quality adjustment data corresponding tothe metadata are read out from the second memory 28 to set a picturequality adjustment condition.

[0091] Metadata relating to a program or a scene may be information suchas an average brightness, a color gain or a hue or may be anidentification code indicative of an image pickup object such as a nightview, fireworks or a clear sky.

[0092] It is to be noted that the present invention can be applied notonly to a TV receiver but also to a set top box which receives a digitalTV signal recorded on a hard disk, a magnetic disk or a like mediumthrough a digital interface such as an interface of the IEEE 1394standards and decodes the received digital TV signal.

[0093] While preferred embodiments of the present invention have beendescribed using specific terms, such description is for illustrativepurposes only, and it is to be understood that changes and variationsmay be made without departing from the spirit or scope of the followingclaims.

What is claimed is:
 1. A picture quality adjustment method, comprisingthe steps of: writing a picture quality adjustment condition for a videosignal as picture quality adjustment data in a correspondingrelationship to video identification information for specifying a videoor characteristic describing information which describes an imagecharacteristic into a memory which is capable of keeping storagecontents thereof without a power supply or with a backup power supply;and reading out, upon outputting of a video, if the video identificationinformation or the characteristic describing information of a videosignal to be outputted and the corresponding picture quality adjustmentdata are stored in said memory, the picture quality adjustment data fromsaid memory and setting a picture quality adjustment condition for thevideo signal to be outputted in accordance with the read out picturequality adjustment data.
 2. A picture quality adjustment methodaccording to claim 1 , wherein said memory is composed of a first memoryand a second memory physically or regionally separate from each otherand the picture quality adjustment data are written in a correspondingrelationship to the video identification information into said firstmemory while the picture quality adjustment data are written in acorresponding relationship to the characteristic describing informationinto said second memory, and then upon outputting of an image, if thevideo identification information of a video signal to be outputted andthe corresponding picture quality adjustment data are not stored in saidfirst memory and the characteristic describing information and thecorresponding picture quality adjustment data are stored in said secondmemory, then the picture quality adjustment data corresponding to thecharacteristic describing information are read out from said secondmemory and a picture quality adjustment condition for the video signalto be outputted is set in accordance with the read out picture qualityadjustment data.
 3. A picture quality adjustment method according toclaim 1 , wherein said memory is part of an area of a recording mediumfrom which the video signal is to be played back.
 4. A picture qualityadjustment apparatus, comprising: a memory capable of keeping storagecontents thereof without a power supply or with a backup power supply;and a control section for writing a picture quality adjustment conditionfor a video signal as picture quality adjustment data in a correspondingrelationship to video identification information for specifying a videoor characteristic describing information which describes an imagecharacteristic into said memory and reading out, upon outputting of avideo, if the video identification information or the characteristicdescribing information of a video signal to be outputted and thecorresponding picture quality adjustment data are stored in said memory,the picture quality adjustment data from said memory and setting apicture quality adjustment condition for the video signal to beoutputted in accordance with the read out picture quality adjustmentdata.
 5. A picture quality adjustment apparatus according to claim 4 ,wherein said memory is composed of a first memory and a second memoryphysically or regionally separate from each other, and said controlsection writes the picture quality adjustment data in a correspondingrelationship to the video identification information into said firstmemory and writes the picture quality adjustment data in a correspondingrelationship to the characteristic describing information into saidsecond memory, and then reads out, upon outputting of an image, if thevideo identification information of a video signal to be outputted andthe corresponding picture quality adjustment data are not stored in saidfirst memory and the characteristic describing information and thecorresponding picture quality adjustment data are stored in said secondmemory, the picture quality adjustment data corresponding to thecharacteristic describing information from said second memory and sets apicture quality adjustment condition for the video signal to beoutputted in accordance with the read out picture quality adjustmentdata.
 6. A picture quality adjustment apparatus according to claim 4 ,wherein said memory is part of an area of a recording medium from whichthe video signal is to be played back.
 7. A video outputting apparatus,comprising a picture quality adjustment apparatus according to any oneof claims 1 to 3 or a picture quality adjustment apparatus according toany one of claims 4 to 6 as a video processing section.
 8. A videooutputting apparatus according to claim 7, wherein said image processingsection demultiplexes digital video data, in which brightness data andcolor difference data are multiplexed, to obtain the brightness data andthe color difference data and performs a picture quality adjustmentprocess for at least one of the brightness data and the color differencedata.